Transmission mechanism for tractors.



R. CRAIG & M. J. & G. A. POLLEY.

TRANSMISSION MECHANISM FOR TRACTORS.

APPLICATION FILED FEB. 24. I913. RENEWED APR. 5. I918.

1 84,606. Patented Nov. 12, 1918.

2 SHEETSSHEET l.

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TRANSMISSION MECHANISM FOR TRACTORS. APPLICATION FILED FEB. 24, 1913.RENEWED APR. 5. 1918.

1,284,606. Patented Nov. 12, 1918.

2 SHEETS-SHEET 2.

Inzeniara fiobekz? Cra Hafiz 06566.7: lycznfrdaffoigg UNITED STATESPATENT OFFICE.

ROBERT CRAIG, OF ROBINSDALE. AND MANFOR-D J. POLLEY AND GEORGE A.POLLEY, OF WINONA, MINNESOTA.

TRANSMISSION MECHANISM FOR TRACTOBS.

Specification of Letters Patent. Patented N 12, 1918 Application filedFebruary 24, 1913, Serial No. 750,129. Renewed April 5, 1918. Serial No.226,965.

To all whom it may concern:

Be it known that we. ROBERT CRAIG, MAN- FORD J. POLLEY, and GEORGE A.POLLEY, citizens of the United States. residing, respectively, atRobinsdale, in the county of Hennepin, and State of Minnesota, Winona,in the county of Winona and State of Minnesota, and Winona, in thecounty of Winona and State of Minnesota. have invented a certain new anduseful Improvement in Trans mission Mechanism for Tractors, of which thefollowing is a full, clear, concise, and exact description, referencebeing had to the accompanying drawings, forming a part of thisspecification.

The tractor transmission mechanism of our invention is provided with animproved driving gear arrangement and devices whereby two speeds may behad whether the tractor is moving forward or backward. Mechanism is alsoprovided for readily throwing a power pulley into or out of drivfi ingrelation with the power plant, as desired.

These and other features of our improved tractor transmission mechanismare described at length in the following description and are illustratedin the accompanying drawings, in which:

Figure 1 is a perspective view of our improved tractor complete.

Fig. 2 is a horizontal sectional view of the transmission gear case.

Similar characters of reference refer to similar parts throughout theseveral views.

Referring to Fig. 1, the tractor there illustrated is provided with apair of rear driving wheels 10, and a pair of front wheels 11. Thewheels 10 are preferably equipped with a plurality of spikes 12, orcleats as shown. These spikes or cleats may or may not be removable, asdesired. Within the hood illustrated at 13, is located the power plant,comprising an internal combustion engine equipped with a coolingradiator illustrated at 14. The engine exhausts through the pipe 15,which preferably leads to a point as high or higher than the canopy 16,under which the o erating levers, etc., are located. A pulley s own at17, is adapted to be operatively connected with the tractor power plantwhen the same is to be used.

The power from the tractor engine is transmitted through a frictionclutch, not shown, to gearing within a gear case 46 and thence to thetractor driving wheels. The case and gearing are clearly shown in Fig.2. A shaft 47, which is operatively connected with the engine, entersthe front of the gear case through a stuffing box 48, and is providedwith suitable ball bearings 49. Keyed to' the inner end of the shaft 47is a beveled or mitered gear 50, as shown.

This gear 50 normally meshes with a pair v of beveled or mitered gears51 and 52, loosely mounted upon a shaft 53, extending transversely ofthe gear case. This shaft 53 has ball-bearings in the walls of the gearcase, and the gears 51 and 52 are preferably provided withball-bearings, as shown.

Keyed upon or otherwise secured to the shaft 53,: one near each endthereof, are spur gears 54 and 55, the gear 55 being of greater diameterthan the gear 54. Hubs or spacing collars Y56 and 57 separate the gearsmounted upon the shaft 53. Each of the beveled gears 51 and 52, isprovided on its inner end with a plurality of square teeth, which areadapted to be engaged by theteeth of a clutch' 58, which is movablelongitudinally of the shaft 53, but is keyed against rotationindependently of the shaft. Suitable means is provided for shifting theclutch 58 into or out of engagement with either one of the gears 51 and52.

Bearing in the casing 46, and disposed parallel to the shaft 53, is .ashaft 59, also provided with ball'bearings, as shown.

. Shiftable longitudinally of the shaft 59, are

gears .60 and 61. These gears arekeyed against rotation independently ofthe shaft 59. Clutch forks 62 and 63 engaging in annular grooves in hubs60 and 61 of the gears 60 and 61, retain the gears in the same positionrelatively to each other at all times and facilitate shifting of thegears. These forks are secured to a shaft 64 hearing in a bracket 65, asshown. The arm 66, with which the shaft 64 is provided, leads to asuitable lever and so afford. means where by the gears 60 and 61 may beshifted relatively to their shaft. as desired. By shifting the shaft 64to the left. the gear 60 may be brought into mesh with the gear 54, andby shifting the shaft 64 in the opposite direction, the gear 61 may bebrought into mesh with the gear Owing to the gear ratios, it will bereadily seen that with the shaft turning at any speed, the shaft 59 willbe rotated at a higher speed if the gear 61 is in mesh with the gear 55,than if the gear 60 is in mesh with the gear 54.

Keyed upon the shaft 59 at approximately the center thereof, is a smallspur gear 67, normally in mesh with a relatively larger spur gear 68,which gear 68 is rigidly secured to the difl'erential gear case 70. Ashaft 69 bears in the wall of the casing 46 and the bracket 70, and isprovided with a stuffing box 71, at the point where it passes throughthe wall of the gear case. A collar 72 is rigidly secured upon the shaft69 and prevents longitudinal movement of the shaft 69 relatively to itsbearings. Disposed in the same plane as the shaft 69. and disposeddirectly opposite the same, is a shaft 73. which bears in the gear casewall, and a bracket 74. This shaft is provided with a suitable stuffingbox 75 and collar 76, as shown, the purpose of both of which isperfectly apparent and need not here be explained. This shaft 73 hasdriven relation to differential gearing within the casing 70*. Theconstruction of standard differential gearing is well known to all thoseskilled in the tractor or allied arts, and need not be here explained indetail. It may be said, however, that if either one of the shafts 69 or73 should temporarily be held against rotation. the other shaft wouldhave its speed of rotation correspondingly increased, due to thedifferential gearing mentioned. The shafts 69 and 73 extend through thegear case and are there provided with small spur gears 77. Each of thesespur gears 77, engages a relatively larger gear 78, which is riveted orbolted to the inner flange 79, of one of the driving wheel hubs 80. Thespecific construction of the rear drive gear case will hereinafter beexplained in detail. The operation of the gearing which has just beendescribed, is as follows:

If it is desired that the tractor move in a forward direction, theclutch 58 is thrown into engagement with the clutch teeth of one of thebeveled gears 51 or 52, according to the direction of rotation of themotor. As previously explained, the gear 51 is normally in drivenrelation with the gear 50. Owing to the fact that the clutch 58 is keyedupon its shaft, the said shaft is turned, thereby rotating the gears 54and 55. keyed thereto. If the tractor is to move ahead at high speed,the shaft 64 is shifted to the right, thereby throwing the gear 61 intomesh with gear 55. If on the other hand, the tractor is to proceed atlow speed, the gear 60 is moved into mesh with the gear 54. In practice,the clutch 58 is out of engagement with each of the beveled gears 51 and52, when any shifting of the gears 60 or 61 takes place in order to doaway with any possibility of stripping the transmission gearing.

If the tractor is to be driven backward, the speed at which it is to bedriven is determined by the adjustment of the gears 60 and 61, and theclutch 58 is moved to the right into engagement with the beveled gear52.

Located near the top of the right hand side of the front of the gearcase, is a gear 81, which is mounted upon a shaft 82. This shaft extendsthrough the gear case and is there provided with a power pulley 17,whichis securely keyed thereto, as illustrated in Fig. 1. The gear 81 isshiftable longitudinally of the shaft 82. but is keyed against rotationindependently of the shaft. When the power pulley is to be utilized, thegear 81 is shifted into mesh with the gear 55 and the clutch 58 is movedinto engagement with either one of the gears 51 or 52 according towhether the power pulley is to be rotated in a clockwise orcounter-clockwise direction. As clearly shown in Fig. 2, the gear 81 isprovided with a grooved hub 83 to facilitate its shifting.

The gear case is made oil tight in order that the gears therein may runin oil, as in manv gear cases heretofore used.

What we claim and desire to secure by Letters Patent of the UnitedStates is:

1. Transmission mechanism consisting of an engine driven shaft. a secondshaft, a pair of gears loosely mounted upon said second shaft driven inopposite directions from said engine driven shaft, means for selectivelvbringing said loosely mounted gears into driving relation to the shaftupon which they are mounted, a third shaft, a pair of gears rigidlymounted upon said second shaft. a corresponding pair of gears on saidthird shaft adapted to mesh therewith, means for selectively bringingsaid third shaft gears into mesh with their corresponding second shaftgears, a power pulley, a driving gear therefor, and means for bringingsaid driving gear into mesh with one of the rigidly mounted gears of thesecond shaft.

2. Transmission mechanism comprising an engine driven bevel gear, ashaft disposed at right angles to the aXis of the gear. a pair of bevelgears loosely mounted on said shaft and meshing with said engine dr vengear, a clutch for connecting either one of said loosely mounted gearswith the shaft upon which they are mounted, a pair of different sizedgears rigidly mounted upon said shaft, a second shaft disposed parallelto the first shaft, :1 pair of gears arranged to mesh with the rigidlymounted gears of the first shaft mounted upon the second shaft andarranged to havelong'itudinalbutnotangularmovement relative thereto,means for causing simultaneous shifting of both gears, said gears beingpositioned relative to the rigidly mounted pair of gears of the firstshaft, so that when two (Jo-acting gears are in mesh the other two areout of mesh, :1 third gear carried by the second shaft and positionedbetween the pair of gears also carried thereby, and difierentialmechanism operated from said last mentioned gear.

Craig In Witness whereof we hereunto subscribe our names in the presenceof two Witnesses. 15

R. S. VAN Banana. C. W. YUs'r. Witnesses to the signatures of Manford J.Polley and George A. Polley:

A. G. MCCALEB, ROBERT F. BRACKE.

